Employee Benefit Plans (Other Details) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 64,847		$ 50,402		$ 42,589
Expense related to defined contribution arrangements	9,287		6,602		7,165
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	3,269		4,256		4,098
Vesting period	4 years
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	10,700		13,010		13,140
Vesting period	4 years
LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	0	[1]	376	[1]	5,056	[1]
Cash Equivalent Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	50,878		32,760		20,295
Darwin LTIP | LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 0		$ 2,194		$ 3,219
Employee Share Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share purchase plan, discount from fair market value	15.00%
Number of shares authorized	1,000,000
2012 Omnibus Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	1,500,000
2012 Omnibus Plan | Performance-based awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
2012 Omnibus Plan | Awards other than performance-based awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years

[1] Includes nil, $2,194 and $3,219 related to the DPUI LTIP for the years ended December 31, 2013, 2012 and 2011, respectively.